The present invention relates to a purifying apparatus using photocatalytic sheets, and in particular, to a purifying apparatus using photocatalytic sheets, which includes ultraviolet lamps and an ozone (O3) lamp which have different wavelengths from one another and are disposed in respective and separate tubes to effectively remove bacteria, volatile organic compounds (VOC), bad odors included in water or air, and these tubes are arranged in a serial or parallel way. Folds are formed at inner ends of the spiral photocatalytic sheets which are in contact with the lamps and the respective lamps are inserted into to increase the contact area with air or water and the contact area with the lamp, thereby preventing the lamp from being damaged.    Document 1 Korean Patent Registration No. 0671232 on Jan. 12, 2007    Document 2 Korean Utility Registration No. 0254611 on Nov. 7, 2001
In general, a purifying apparatus has been known, which allows a semiconductor used as an electrode to be contacted with TiO2 having chemical stability and facilitating treatment and supply, and irradiates UV light output from a UV lamp onto a photocatalyst separated by holes and having positive and negative charges, so that hydration radicals generated at this time carry out sterilization and deodorization.
Such a purifying apparatus allows the photocatalytic sheet coated with the photocatalyst to be plurally stacked to purify air or water passing through the sheets. However, such a structure occupies a large volume so that its efficiency is low.
Document 2 is intended to obtain a high efficiency in a small space, which corresponds to the case that the photocatalytic sheet has a spiral shape. Accordingly, there occur many contacts between air or water and the photocatalytic sheet while the air or water flows along the spiral passage formed by the photocatalytic sheet.
However, even when the spiral-shaped purifying apparatus uses one spiral photocatalytic sheet, its contact area is not sufficiently large. The structure using one UV lamp makes it difficult to obtain a significant sterilizing effect. That is, the sterilizing abilities become different from each other depending on the light wavelengths irradiated from the UV lamp, and VOC removal or deodorization becomes also different.
None the less, the conventional case has a weak sterilizing ability even though it uses the UV lamp having a large range of wavelengths to save the space.
An inner end of the spirally wound photocatalytic sheet is direct contact with the UV lamp. Accordingly, the sharp contact end may damage the UV lamp at the time of producing, assembling, disassembling, or repairing the lamp.
In addition, according to the conventional art, purification of water or air depended on the spiral photocatalytic sheet only. This was due to the fact that the photocatalyst could not be coated on other portions of the purifying apparatus.
In particular, the case has a small inner diameter and a long length so that the photocatalyst could not be coated on the inner side of the outer case, that is, the inner side of the outer case where the photocatalyst and the UV lamp are to be inserted.
In view of the problems mentioned above, the present invention is thus directed to a spiral photocatalytic sheet, which allows its structure to be changed to more increase the contact area with water or air and to prevent the UV lamp from being damaged in a portion in direct contact with the lamp.
In addition, UV lamps having respective different wavelengths optimized for sterilization, deodorization, and purification are coupled with each other in order to increase the ability of purifying water or air.
In addition, a photocatalytic tube is inserted between the spiral photocatalytic sheet and the outer case for allowing more water or air to be in contact with the photocatalyst and a spiral photocatalytic sheet and a UV lamp are inserted therein so that the purification ability is enhanced.